<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Header Signer Interface used to apply Header-Based Signature to a message
 *
 * @package    Swift
 * @subpackage Signatures
 * @author     Xavier De Cock <xdecock@gmail.com>
 */
interface Swift_Signers_HeaderSigner extends Swift_Signer, Swift_InputByteStream
{
	/**
	 * Exclude an header from the signed headers
	 *
	 * @param string $header_name
	 *
	 * @return Swift_Signers_HeaderSigner
	 */
	public function ignoreHeader($header_name);

	/**
	 * Prepare the Signer to get a new Body
	 *
	 * @return Swift_Signers_HeaderSigner
	 */
	public function startBody();

	/**
	 * Give the signal that the body has finished streaming
	 *
	 * @return Swift_Signers_HeaderSigner
	 */
	public function endBody();

	/**
	 * Give the headers already given
	 *
	 * @param Swift_Mime_SimpleHeaderSet $headers
	 *
	 * @return Swift_Signers_HeaderSigner
	 */
	public function setHeaders(Swift_Mime_HeaderSet $headers);

	/**
	 * Add the header(s) to the headerSet
	 *
	 * @param Swift_Mime_HeaderSet $headers
	 *
	 * @return Swift_Signers_HeaderSigner
	 */
	public function addSignature(Swift_Mime_HeaderSet $headers);

	/**
	 * Return the list of header a signer might tamper
	 *
	 * @return array
	 */
	public function getAlteredHeaders();
}
